Refrigerator construction



y 15, 1962 J. w. PULASKI 3,034,316

REFRIGERATOR CONSTRUCTION Filed Nov. 12, 1959 fl VFIGZ TOHN W. PULASKI H l S ATTORNEY INV EN TOR United States Patent Filed Nov. 12,1959, Ser. No. 852,364

3 Claims. (Cl. 62-273) The present invention relates to refrigerator cabinets and is more particularly concerned with a construction thereof-for preventing the accumulation of moisture and frost in the insulated cabinet wall spaces.

The prevention of moisture accumulation within the insulated walls of a refrigerator cabinet constitutes one of the major problems in the design and insulation of such cabinet. Such moisture may enter the insulated walls either from the atmosphere outside the cabinet or from the air within a cabinet storage compartment, the latter constituting one of the principal sources of such moisture. Each time the refrigerator door or other closure member is opened moist ambient air enters the storage compartment. Upon closing of the closure member, the air within the compartment is compressed slightly with the result that the moist air is in eifect pumped through various leakage paths, as for example between the usual breaker strip and the compartment liner, into the insulation surrounding the compartment. While thcse small leakage paths permit the moist air to be pumped into the insulated space upon door closure, they are not sufficiently large to provide for its return to the interior of the compartment by normal air circulation'therethrough. As a result the moisture which enters the insulation collects on the colder liner'surfaces and unless some means is provided for disposing of this moisture, it will eventually detract from the insulating value of the insulation. At-

'tempts to solve this problem by completely sealing all openings between the compartment and'the insulated space been found to be too expensive or otherwise not practical.

The present invention is based on the discovery that a very effective means for solving the moisture problem comprises the deliberate provision of air passageways through the compartment walls and into the adjacent insulated spaces, these passageways being so constructed and arranged that the moisture passing therethrough can readily migrate (due to vapor pressure differential) back into the compartment to accumulate or collect on the evaporator provided in that compartment.

Accordingly, it is an object of the present invention to provide a refrigerator cabinet of a construction suchthat substantially all of the moist air entering the insulation from the refrigerated cabinet will be restricted to selected areas from which the moisture can migrate back into the compartment.

Another object of the invention is to provide a refrigerator cabinet liner including passageways in the walls thereof for the controlled flow of moisture between the interior of the liner and the insulated spaces surrounding the liner.

Further objects and advantages of the invention will become apparaent as the following description proceeds and the features of novelty which characterize the invenforming a compartment including top and side walls and having an access opening at the front thereof, and heat insulating material in the space surrounding the liner. A "plurality of louvers provided in theside and top walls of the .liner and extending outwardly into the insulated spaces surrounding the liner provide passageways for the flow of 3,9343% atentedMay- 15, 1962 2 moist air from the compartment into the insulated spaces during the closing of the door or other closure member for the compartment access opening. These passageways and the .louvers defining the passageways are so constructed and arranged that moisture collecting on the ice - exterior surfaces of the liner will migrate or flow back into the liner during normal or defrost operation of the refrigeration system thereby preventing continued accumu! lation of moisture within the-insulated spaces.

For a better understanding of the invention reference .a refrigerator cabinet including an outer shell 1, an inner liner 2 forming a fresh food storage compartment 3 and an inner liner 4 forming. a freezer compartment 5. The spaces between the outer shell and the inner liners and the space between the two inner liners are filled with suitable heat insulating material 6. Except for the access openings at the front of the compartments 3 and 5, it will be understood that this heat insulation material 6 completely surrounds each of the compartments for insulating the compartments from one another and from the outer shell 1. In the illustrated embodiment of the invention the access opening to'the upper or fresh food storage compartment is closed by a door 9 while a closure member to the access opening to the freezer compartment 5 is in the form of a drawer front 10 forming part of a drawer structure including slide and guide means 11 and a storagebasket or pan 12 shown in phantom lines.

The fresh food storage compartment 3 is maintained at above freezing storage temperatures by means of an evaporator (not shown) while the freezer compartment 5 is maintained at below freezing temperatures by means of an evaporator 14 extending along the rear and bottom walls thereof, these evaporators being suitably connected to a condensing unit mounted in the machinery compartment 15 and including a compressor 16';

One of the principal sources of moisture'inthe insula tion 6 is that condensing fromthe air pumped into, the

insulated wall structure of the cabinet during closure of closure members and the cabinet'front are sealed by either gasket 19 or gasket 20 during the closing operation. The excess air within the compartment is forced to pass through various leakage paths'in the compartment walls into the insulation. One such path for the forced flow of air is that between the usual breaker strip or strips indicated by the numeral 21 provided around the access openings between the liners 2 and 4 and the face of the cabinet These leakage paths, however, are relatively small and are not effective for migration of the moisture back into either of the compartments. As a result, unlesssome means are provided for disposing of the moisture collecting within'the insulation in the form of either a liquid condensate with reference to the liner 2 or as solid ice or frost with reference to the liner 4, there will be a; continued buildup of moisture in the insulated space with the gradual and continued deterioration of the insulating values of the insulation 6.

Most of the moisture in the insulated spaces will initially collect on certain portions of the outer liner surfaces. Du-ring'operation of the refrigeration system v including the compressor 16 and the two evaporators, the

"liners- 2 andgd 'are cooled below ambient, the liner 4 normally operating at temperafrost.

to temperatures substantially tures substantially, belowfreezing. Because moisture ,tendsto migrate to the coldest avail-able surface, moisture .inthevinsulation 6 adjacent the liner 2 tends to migrate downwardly towards the freezer compartment and ultimately collect ronvthe outer surface of the upper freezer wall 17 along with any moisture from theinsula'tion adjapassageways. As a result, this moist air is preferentially cent that wall. 'In addition any condensation on the outer surfaces of the liner 2 tend to flow downwardly along the side walls ofthe liner and thus also reaches a point adj-a- {cent the'upper wall 17 of the freezer compartmenh;

Since the freezer liner 4-presents the coldest surface to moisture standpoint since moisture in this partof the cabinet structure will usually be in the form of ice or restricting the' collection of frost on the freezer'liner 4 i {to selected areas from which it can be transferred back into-the freezer compartment either by vapor migration the insulation 6, theinsulation'surrounding the freezer '7 zcompaltrnent 5 presents the greatest problem from a By, the present invention means are provided for to the colder evaporator '14 or in the form of defrost water during defrosting of the freezer compartment. This is 'achieved'by providing a plurality of passageways in the walls of the liner 4 of a size such that substantially all of the air. pumped into the insulated spaces upon clo- -sure of the closure member 10 will pass through these pumped into the insulated areas adjacent the louvers rather than through the smaller leakage paths around the inner edge of the breaker strip 21 and into areas in the insulation from which the, moisture in the air would tend to migrate to the outer surface of the colder bottom wall a 37 adjacent the evaporator 14. With the insulation 6 held in spaced relationship with selected areas of the liner 4, much of this moist air will collect within the vacancies or voids {38 and 39 adjacent these louvers from which much of the moisture contained therein will migrate back throughQthe open louversvinto thefreezer compartment and ultimately collect on the evaporator 14. This migra- .tion particularly from the .are'asadjacent the top wall louvers is further facilitated by a natural circulation of air upwardly through the relatively warm portions of the insulation 6 adjacent the side walls of the liner 4 and downwardly through the upper louvers 25 and the colder interior of compartment 5. This circulation also causes some of the moisture collecting on the adjacent lower surfaces oftheupper liner 2 to pass into the lower coml'partment in the form of vapor and collect on the evaporator' 14.3

passageways into selected portions of the insulated space Y around the freezer liner remotefrorn the liner walls closest tothe evap'oralton In accordance with the preferred embodiment of the invention these passageways'are providedon the'top wall 17 and the side walls 24 of the compartment S by striking from the metal forming the "liner "4 a plurality of louversp With reference to the ;drawing, the numeral 25 indicates louvers'struck from ithe top wall 17 of the linerto form passageways 26 while the numeral 27 "indicates louvers'27 struck from the side lwalls of the liner to form passageways 28.

The louvers 25 in the topv wall of the liner preferentially L extend substantially the entire width ofthis wall, a series of 'suchlouvers and passageways 26 being provided in this wall and opposite thebottom' wall of the fresh food compartment 3. These louvers 25 open outwardly and forwardly into the insulated space between the upper and-lower compartments and hold the adjacent portions of the insulation '6'in spaced relationship withthe top ".walll'l 'of' the'liner'ig By having the passageways 26 iforrn'edby these louvers opening forwardly outside of the j'berpassed into or through the openings 26.

The louvers 28 on'the side walls 17-also open'ou-t- 'wardly into the insulated spaces adjacent these walls and upwardly so that thelouvers 27 in effect also form drain f'troughs'for the collection of any defrost water formed ion the side Walls24 whereby such water will flow back into the compartment 5 during'defrost periods when the During defrosting 'of the freezer compartment, when the evaporator =14 and the liner-wall are brought to tem peratures above freezing, ice 'or frost that has collected on the outer surfaces'of the top wall 17and the side walls 24 will melt and flow through the louvers 2S and.27 back into, the interior of the compartment 5. Thelou-vers 27 'whichopen outwardly and upwardly into the insulated space intellect form troughs for receiving this defrost Water and directing it into the interior-of the liner 4. If de- 7 sired, the top wall 17 of the compartment 5 may be sloped slightly inarearwardly direction in order that melting frost on the upper surface of this wall will more readily flow through thepassageways 26 into the compartment 5.

From the above description it will be seen that the present invention provides a simple andelfective means for preventing moisture or frost accumulation in the insulatgliner 4, the passageways 26 are hidden from view when, 7 'fthe drawer It! is open and arealso so arranged ithat "during normal use of the freezer compartment 5 articles 'ibeing' inserted into the compartment cannot accidentally to preventloose fibersin the fibrous insulating material "6 from falling through the openings 26 or 28 into the "interior of the compartment 5.

As previously indicated the passageways 26 and '28 are a '"designed to provide combined areas sufiicient so that subrstantially all of the excess air compressed within the com- --partment 5 as 'the drawer front-ll comes into'sealing con- -tact'with'the face of ,the cabinet will flow through these ed walls of the refrigerator by,'in effect, restricting the frost or moisture accumulation to selected areas of the outer surfaces of the, liner in such a manner that the transfer thereof back into the linerfor disposal outside of the refrigerated cabinet can be readily accomplished. While ,there has been shown and described a specific embodiment of the invention, it is to be understood that the invention is not limited thereto and it is intended bythe-appended claims to cover all modifications Within the spirit and scope of the invention.

I What I claim as new and desire to secure by Letters Patent of the United States is:

1. A refrigerator cabinet comprising, (a), an outer shell,

(b) an inner liner spaced from said outer shell and forming a compartmentincluding top'and side walls and having an access opening at thefront thereof, (0) an evaporator in said compartment, a ('d) fibrous heat-insulating material in the space'surroundingrsaid liner, 7 i a (e) a closure member forrclosing'said access opening (f) said side walls having'a plurality of horizontally extending louvers therein opening outwardly-and upwardly into the insulated spaces adjacent said walls,

(g) said top wall having'a plurality of spacedlouvers opening upwardly and forwardly into the insulated space above said compartment,

1 (h) said louvers maintaining the adjacent insulation in spaced relation with said liner and providing passageways for migration of water vapor from said i-nsulation into said compartment, 7 ('i) each of said louvered walls havinga moisture'pe'rviousretaining element interposed between the louvered wall and-saidrheat-insulating material to preventsaid material'from entering the louvers,

(j) The combined areas of the passageways formed by said louvers being sufficient so that substantially all of the additional air pumped into said compartment upon closure of said closure member will flow through said passageways and into the insulated areas adjacent said louvers whereby moisture carried into said insulated areas by said air will collect on the outer surface areas of said liner adjacent said louvers and be transferred back into said liner through said passageways.

2. A refrigerator cabinet comprising,

(a) an outer shell,

(b) an inner liner spaced from said shell and forming a freezer compartment including top and side walls and having an access opening at the front thereof,

(c) a closure member for closing said access opening,

(d) fibrous heat-insulating material in the spaces surrounding said liner,

(2) a refrigerant evaporator in said compartment,

(1) said side walls having a plurality of horizontally extending louvers adjacent the bottom portion thereof opening outwardly and upwardly into the insulated spaces adjacent said walls,

(g) said top wall having a plurality of spaced louvers opening upwardly and forwardly into the insulated space above said compartment,

(h) said outwardly extending louvers maintaining the adjacent insulation in spaced relation with said liner and providing passageways for migration of water vapor from said insulation into said compartment,

(i) each of said louvered walls having a moisturepervious retaining element interposed between the louvered wall and said heat-insulating material to prevent said material from entering the louvers,

(j) the combined areas of the passageways formed'by said louvers being sufiicient so that substantially all of the additional air pumped into said compartment upon closure of said closure member will flow through said passageways and into the insulated areas adjacent said louvers whereby moisture carried into said insulated areas by said air will collect on the outer surface areas of said liner adjacent said louvers and be transferred back into said liner through said passageways.

3. A refrigerator cabinetcomprising,

(a) an outer shell,

(b) an inner liner spaced from said outer shell and forming a compartment including top and side walls and having an access opening at the front thereof,

(c) a closure member for closing said access opening,

(d) fibrous heat-insulating material in the space surrounding said liner,

(e) an evaporator positioned within and along the rear and bottom walls of said compartment,-

(f) said side Walls having a plurality of louvers adjacent the bottom portion thereof opening outwardly and upwardly into the insulated spaces adjacent said walls,

(g) said top wall having a plurality of spaced louvers opening upwardly and forwardly into the insulated space above said compartment,

(h) said outwardly extending louvers maintaining the' 2 adjacent insulation in spaced relation with said liner and providing openings for the circulation of air through said insulation between said side wall louvers and said top wall louvers,

(i) each of said louvered walls having a moisture pervious retaining element interposed between the louvered wall and said heatinsulating material to prevent said material from entering the louvers,

(j) the combined areas of the passageways formed by said louvers being suflicient so that substantially all of the additional air pumped into said compartment upon closure of said closure member will flow through said passageways and into the insulated areas adjacent said louvers whereby moisture carried into said insulated areas by said air will collect on the outer surface areas of said liner adjacent said louvers and be transferred back into said liner through said passageways.

References Cited in the file of this patent UNITED STATES PATENTS 2,019,194 Munters Oct. 29, 1935 2,084,883 Atchison June 22, 1937 I 1 2,515,212 Gifiard' July 18, 1950' 2,552,345 Phillip May 8, 1951 2,617,268 Ashby Nov. 11, 1952 2,639,593 Deutgen May 26', 1953 j 

